# ANDE-Castor

> former American atmospheric density research satellite

**Wikidata**: [Q115927264](https://www.wikidata.org/wiki/Q115927264)  
**Source**: https://4ort.xyz/entity/ande-castor

## Summary  
ANDE-Castor was a former American atmospheric density research satellite launched in 2009. It was designed to study variations in atmospheric drag and improve models of upper-atmosphere density.

## Key Facts  
- Launched on July 15, 2009, aboard Space Shuttle Endeavour during mission STS-127  
- Part of the Atmospheric Neutral Density Experiment 2 (ANDE-2) project  
- Mass at launch: 47.45 kg; Diameter: 0.4826 meters  
- Operated by NASA's Space Test Program and Lyndon B. Johnson Space Center  
- Re-entered Earth’s atmosphere on August 18, 2010  

## FAQs  
### Q: What was the purpose of ANDE-Castor?  
A: ANDE-Castor was built to measure atmospheric density and improve orbital drag models. Its data helped refine predictions of satellite orbital decay and atmospheric behavior.  

### Q: When was ANDE-Castor launched and deployed?  
A: It was launched on July 15, 2009, and deployed into orbit on July 30, 2009, from the Space Shuttle Endeavour.  

### Q: How long did ANDE-Castor remain in orbit?  
A: The satellite remained in orbit until it re-entered Earth’s atmosphere on August 18, 2010.  

## Why It Matters  
ANDE-Castor played a key role in advancing understanding of atmospheric drag effects on satellites in low Earth orbit. By collecting precise measurements of neutral density, it contributed valuable data for improving space situational awareness and satellite tracking models. These insights are essential for predicting orbital lifespans, reducing collision risks, and supporting future spacecraft design. Though operational for just over a year, its findings supported broader efforts in space science and defense-related satellite operations.

## Notable For  
- One of two active spheres in the ANDE-2 experiment (paired with ANDE-Pollux)  
- Used as both a research satellite and amateur radio satellite  
- Designed for dual military and scientific purposes under NASA’s Space Test Program  
- Provided high-resolution atmospheric drag data through GPS-based tracking  

## Body  
### Mission Overview  
ANDE-Castor was one half of the Atmospheric Neutral Density Experiment 2 (ANDE-2), a joint effort between the U.S. Naval Research Laboratory and NASA. Its primary objective was to monitor changes in atmospheric density by measuring deceleration caused by atmospheric drag while maintaining a known ballistic coefficient.

### Design and Specifications  
The satellite was spherical, with a diameter of 0.4826 meters and a total mass of 47.45 kilograms at launch. It featured retroreflectors and an onboard GPS receiver to enable precise orbit determination via ground-based laser ranging and radio telemetry.

### Launch and Deployment  
Launched on July 15, 2009, at 22:03:10 UTC from Kennedy Space Center Launch Complex 39A aboard Space Shuttle Endeavour (mission STS-127), ANDE-Castor was deployed into orbit on July 30, 2009, along with several secondary payloads including AggieSat2 and Bevo-1.

### Operations and Data Collection  
During its mission, ANDE-Castor transmitted data via amateur radio frequencies, enabling global participation from ham radio operators. This made it useful not only for scientific analysis but also for educational outreach and public engagement.

### End of Mission  
After approximately 13 months in orbit, ANDE-Castor experienced orbital decay due to atmospheric drag and re-entered Earth’s atmosphere on August 18, 2010.

## Schema Markup  
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  "@type": "Thing",
  "name": "ANDE-Castor",
  "description": "Former American atmospheric density research satellite.",
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## References

1. [Source](https://space.skyrocket.de/doc_sdat/ande-2.htm)
2. [Source](https://www.ne.jp/asahi/hamradio/je9pel/dragonst.htm)
3. Jonathan's Space Report
4. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=2009-038F)
5. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2009-038F)
6. [Source](https://ilrs.gsfc.nasa.gov/docs/andehw.pdf)
7. [Source](https://www.eoportal.org/satellite-missions/ande-2)
8. [Source](https://ilrs.gsfc.nasa.gov/missions/satellite_missions/past_missions/anda_general.html)